Treating animal tissue



' Patented June 15, 1943 UNITED STATES PATENT OFFICE samm m...

John M. 'Bamsbottom and Levi 500 PM Chicago, 111., more to Industrial Patents Corporation, Chicago, 111., a corporation of Delaware No Drawing.

Original 1941, Serial No. 382,590. Divi plication December 31, 1941,

application March 10,

ded and this ap- Serial No. 425,208

Claims. (Cl. 99-107) This invention relates to the treatment of animal tissuesland has to do particularly with the treatment of flesh and intestines with plant enzymic material to improve the value thereof. One of the objects of this invention is to provide a methodwhereby animaLtissue may be rendered tender and improved in other properties.

Another object of this invention is to provide a method whereby the flesh of edible animal carcasses may be rendered tender.

Another object of this invention is to provide a methodwhereby-animal intestines may be ren-' -dered tender and more adaptable for use as sausage casings. I

Another object of this invention is to provide a method of treating natural sausage-casings to increase the stretchabiiity of the casings and to increase the stufiing capacity of the casings.

Another object of this invention is to provide a method whereby the smoking properties of the casings may be altered.

Another object of the invention is to provide a method whereby such tough casings as hog casings and Indian sheep casings maybe tendered Y to any desired extent and rendered uesful in the manufacture of high grade sausage products which require a tender casing.

Still another object of the invention is to so alter normally tough meat and other animal tissue as to render the same substantially more tender and, therefore, more at for human consumption.

A further object of the invention is to provide meat and animal casings which have been treated so as to materially improve the physical properties thereof, and which in particular have had the tenderness properties thereof greatly increased.

A further object of the invention is to provide a tenderlzed natural casing for use in making sausages and the like.

- A still further object of the invention is to provide a hog, beef and/or Indian sheep casing having a tenderness at least equal to that of untenderized domestic sheep casings.

Another object of the invention is to provide hog casings, Indian sheep-casings, etc., having a tenderness greaterthan that of untenderized or untreated domestic sheep casings;

Another object of the invention is to so modify the tissue of certain animal casings heretofore considered unsatisfactory for making sausages provide me tissue and natural casings which have been tenderiaed by treatment with enzyme material. Other objects and advantages of this invention will become apparent from. the description and claims which follow.

The process isapplicable to the treatment of various-types of animal tissue, such as wholesale or retail cuts of meat, including beef and-pork.

It is also applicable to the treatment of meat in various degrees of comminution, such as hamburger, sausage and the like. The treatment of sausage may take place before or after the meat is stuffed into casings.

The invention is particularly adaptable to the treatment of hog casings, Indian sheep casings, and beef casings although it is not limited to the treatment of these specific types of materials.

' Natural casings, as distinguished from artificial or synthetic casings, are prepared from the in.- testines of edible animals, such as cattle, swine and sheep. After the intestines are removed from "the carcass. they are cleaned and a tubular membrane appropriate for sausage casings is andthelikeastorenderthesameofthesameusefulness as domestic sheep casings.

Still another object of the invention is to render the manufacture of sausages and'the like more economical by making it possible to utilize in'such manufacture inherently tough natural casings which wereheretofore considered unsatisfactory for the purpose.

A still further object of the invention is to obtained. q

Sheep casings command a higher price because they generally possess more desirable physical properties than hog casings, Indian sheep casings and beef casings. Hog casings are suited for the The present invention contemplates the treat-' ment of animal tissue including natural casings prepared from animal intestines'with a solution of a proteolytlc enzyme obtained froma plant,

such as plant juice or extract containing a pro- I teolytic enzyme, and controlling the action of the plant enzyme on the tissue in such a .way that the desired physical properties of the tissue are improved efficiently and quickly without undue digestion or other undesirable effects.

We are aware that it has been proposed heretofore to treat meat with'certain enzymes to obtain tendering. For example, the patent to Paddock, et 9.1., United States Patent No. 2,043,392, disclom the injection of proteolytic enzymes into the vascular system of carcass beef and then holding the treated product under refrigeration. There is no disclosure in that patent of treating natural casings with an enzyme nor the, treatment of animal tissue under the conditions of the present invention whereby applicants results could be obtained. The patent to Marcano, United States Patent No. 441,181; discloses the preparation of a meat peptone in which the meat is completely disintegrated into a liquid or soluble pasty form. The Marcano patent has no disclosure of tendering any kind of animal tissue.

. hasbeen found that these proteolytic enzymes According to the present invention, animal tisare generally prepared from, fresh or frozen enzymic plant juices or extracts, which have not been subjected to a temperature sufficiently high to destroy theenzymatic action. Included among the plant juices and the corresponding proteolytic plant enzymes which may be employed in the present process are milkweed juice containing asclepain, papaya juice containing papain,

pineapple juic containing bromelin, fig Juice containing ficin, osageorange juice containing macin and mushroom juice containing mushroom pro-' teolytic enzyme; The natural plant juices containing a proteolytic enzyme and/or mixtures thereof are usually employed in preparing the treating solution, but other solutions of the plant proteolytic enzyme or enzymes can be used. Solutions containing about 1 part of enzymic plant juiceto about 5 or 6 parts or more of water are oftenused under the conditions of treatment herein specified, although satisfactory results may be obtained by using undiluted extracts or extracts diluted with water up to about 200 parts of water. ture of the tissue treated, the activity and typ of enzyme employed, and the other conditions i such as time, temperature and method'of oper ation.

The enzymic juice or extract maybe obtained by pressing the fruit in the case of the pineapple, osage orange, papaya and fig enzymes.

pressing the plant. The milkweed, osage orange, p p ya and fig enzyme extract may be recovered by-pressing the freshleaves, stems, stalks'and sap wood of these plants.- The proteolytic'plant enzyme may be isolated from the appropriate juice or extract sourceby any method suitable for the isolation of a proteolytic enzyme. These methods include precipitation with'ethyl alcohol, acetone, methyl alcohol, salts and the like. Solutions containing the natural proteolytic plant enzyme Juice, for example papaya juice, milkweed juice and/or pineapple juice, in concentrations of a fraction'of a percent to 100% may be satisfactorily employed. Corresponding solutions of the isolated'enzyme may conta in as low as; 0.002% of the enzyme or even lower, and as high as 5% or more of the enzyme. ple, 'a solution containing preparations of about 0.005% to 0.05% 'of the'enzyme is generally satisfactory, although solutions containing active plant enzymes in larger amounts, for example 0.05% to 0.5% or more are contemplated for our use. Solutions 'of'the lower range are usually used for treating meat. Solutions of the higher'range,

approximately 10 times the concentration for tenderizing meat, are more satisfactory for treating intestinal tissue, such as natural casings.

In the use of solutions of the plant enzymes it For exam by any of themethods described hereinbefore is subjected to a temperature within the range of enzyme activity but} above refrigeration tem- The concentrationsvary with the na- The ,mushroom enzyme juice may be obtained by are generally most active when employed in a solution having a hydrogen ion concentration approximating that of the extract or juice. However, these enzymes are active when used in solutions varying over a. wide range of hydrogen ion concentrations, e. g., a pH between about 3 or 4 and 8.5. It is advantageous to maintain the pH value below '1 for maximum-enzyme activity, for advantages in dye absorption by the products, and, particularly, for treating meat and stuffed sausages in order to avoid an alkaline reaction on the meat which would stimulate undesirable bacterial growth.

The natural juice or other solution of proteclytic plant enzymes may be applied to the tissue in any suitable manner as by washing, soaking, mecting, sn y s, d p s r wipin It will be understood that the time of treatment, the temperature of treatment, and the concentration and activity of the solution are all variable and should be adjusted to secure the desired extent of tendering, which is dependent upon the type and the initial toughness ofthe tissue. The activity of the proteolytic plant enzyme increases with increasing temperature until a condition of greatest activity is generally reached at temperatures between about and 160 F. The enzyme activity is destroyed at a temperature between about 160 and 185 F. These temperatures vary slightly with 1 the different enzymes. For example, papain or papaya juice is operative at slightly higher temperatures, -e. g., 175 F., whereas the mushroom enzyme may sometimes be inactivated at temperatures of about to F.

The product previously treated with the enzyme peratures, preferably between 60 and 140 F. and maintained at such temperature in contact with the previously applied proteolytic enzyme for a sufllcient length of time to. permit the enzyme 1 to act upon'the tissue, whereby the desired alterciently high, for example, to a temperature between about and F. to inactivate the enzyme and avoid excessive action on the tissue. As an alternative method, the treated product may-be thoroughly flushed with water before or after the final heat treatment to remove the major portion of the enzymatic material. The action of the enzyme may be terminated by other means than heating or" washing, such as the application of a suitable chemical reagent.

In the treatment of meat tissue the enzyme solution may be applied to the meat by any ofthe foregoing methods. The previously treated meat is then held at a temperature of above about 60 F. and within the range of enzymic activityuntil the desired degree of tenderization takes place. The temperature of the meat is then raised to a point at which the treating enzyme is substantially inactivated. This tenderization process may be accomplished by gradually heating the meat to which the enzyme has been applied from room temperatureto cooking temperature and finally enzyme inactivation temperature. The temperature rise through the gradient is at such a rate that the meatis tenderized by the enzyme in its active range. When-the desired degree of tendering results, the temperature is substantially raised to stop further enzymic action. The

tissue to the desired extent, e. g.,

yp quantity and activity of the enzyme, determine the time and temperature of heat treating.

As an illustration of the tenderizing of meat by this process, a normally tough muscle from the hind shank of the right side of a beef carcass (peroneus tertius) was treated with an enzyme solution containing preparations of about 0.012% asclepain, 0.012% 'papain, 0.008% ficin, 0.015% macin, 0.035% bromelinor 2% mushroom enzyme by injecting the solution into the primary artery supplying the circulatory system or the cut. The amount of enzyme solution injected was about 8% of the muscle weight. An enzyme-treated right side muscle and a non-treated control left side muscle were cut into slices about one-half inch thick. These slices were heated gradually from room temperature to a temperature of about 160 F. in. about 10 to minutes. The enzyme was then inactivated by quickly raising the temperature substantially above this value. pared with the cooked control. In all cases the treated muscle slices were tender whereas the control muscle slices were tough.

It is possible to similarly prepare treated beef rounds to obtain steaks and roasts which when heat treated first in the active enzyme temperature range followed by'a high heat treatment to inactivate the enzyme will yield cooked cuts substantially more' tender thanthose not so treated with enzymes. In all these treatments the steaks and roasts are fried, broiled or roasted to an in-.- side temperature of at least 160 F. and tenderness' comparisons made on the cooked meat. of course with these larger cuts longer periods of treatment, for example, up to 1 hour or more, are generally necessary in order to raise the temperature throughout the meat, through the active enzyme range.

In treating the beef rounds the enzyme solution alternatively may be introduced into the cut by means of hypodermic'needles until the desired amount of enzyme solution based on the weight of muscle is obtained. For example, an aqueous solution containing preparations of about 0.012% asclepain, 0.05% mushroom enzyme, 0.012% papain, 0.005% ficin, 0.015% macin, or about toughness and size of the meat cut, and the v The cooked, treated product was com- I 0.035% bromelin or an equivalent dilute plant juice may be injected by needles into the cuts of meat or into the circulatory system of a meat cut or a carcass in an amount equal to about 6% of the weight of the meat to prepare it for the heat tenderizing treatment.

In the treatment of sausage casings, the natural juice or other solution of proteolytic plant enzyme may be applied to the casing in any suitable manner as by washing or soaking the casings in the solution, adding the enzyme or juice to the sausage cook water or spraying, dipping or wiping the casing with the enzyme solution or juice after the casing has been stufled with sausage meat. The casing may be treated, however, before or after stufling and greater improvement in stretchability is sometimes obtained by treatment before stufllng.

The casing with the applied enzyme may be heated to a temperature above about 60 F., for example, between about 110 and 140 F., and maintained at such temperature for a sumcient length of time to permit the enzyme to attack the A to 3 hours. temperature is then raised to a point high enough to destroy the major portion of the enzyme and avoid excessive action on the casing.

v casings.

' with one of the foregoing aqueous be raised to 170 operation the temperature in the smoke houseraised through a wide range, at least a may be v portion of which is in the field of enzymic activity, and the temperature rise through this gradient may be rather slow.

The "present invention may s'tufllng, basins or receptacles may be placed at the end of a conventional stufilng table. One basin is equipped with an overflow and warm water is passed continuously through the basin; the other basin may serve as a receptacle for the juice or juices or other solution of proteolytic plantvenzyme or enzymes. A satisfactory aqueone solution may be prepared containing preparations of about 0.12% asclepain, 0.12% P Pain, 0.08% ficin, 0.15% macin, enzyme, or an equivalent quantity of plant juice; e.g.-, 15% pineapple Juice. Theconcentration and activity of the solution will vary with the type of easing whichis to be treated but the above values are good for average production. Theenzyme solution is then placed in the proper receptacle.

warm running water basin, immersing the sausages 2 or 3 times to rinse off particles of meat from the surface of the casings. The sausages are then immersed 2 or 3 times in the enzyme solution, care being taken to have the solution reach all portions of the outside surface of the In the commercial treatment of natural casings, we prefer to spray the stuifed casings en yme solutions containing about 0.1% papain, ficin or asclepain, 0.5% mushroom juice enzyme, or about 0.35% bromelin.

It will be understood, of course, that the time of treatment, the temperature of treatment, and the concentration and activity of the solution are all variable and may be adjusted at will to secure the desired alterations in the physical properties of the casings,.and are dependentupon the use to which the casings are to be put and the initial properties of the casings After the application of one of uct with the enzyme or enzymes placed in a tempering room for a period of about 1 hour and 30 minutes with their temperature of from to 120 F., preferably about 80 to F.,

anda relative humidityof about 80% to 85%. The product is then removed tb a preheated sufllcientlyhigh to cure the product, for example, at a temperature of from to 170 F. The product is usually kept in the smoke house for about 45 minutes up to 1 or 2 hours, during which time a gradual increase in temperature from about 120 to or F. may be obtained over a period of about 1 hours. The air temperature, if desired, may then to 200 F., for example, to a temperature of about F. and maintained at this omit the separate tempering Y be practiced by treating the casings after stufling as wellas before stufling. In the treatment of casings after or 0.5% mushroom After the sausages are stuffed and linked, the operator clips the sausages in the the enzyme solu- I tions by any of the foregoing methodsthe prodthereon may be temperature for about minutes. Preferably after the curing operation, the product may be cooked in water or steam in which case it is desirable not to exceed a temperature of about 180 F. The preferred cooking treatment, however, is to place the frame with the smoked sausage links in a cooking chamber where the sausages are sprayed with hot water ata temperature of about 170 F. for about 12 to 15 minutes, thereby init is difficult to break or puncture a stuifed sausage by bending, biting, chewing or pulling, whereas the casings treated by the present invention are easily broken by bending and may be readily punctured by gentle pressure with a finger or thumb.

The improvement in and uniformity of tenderness of the treated casings may be more precisely shown by penetrometer measurements 'of the force necessary to puncture a sausage casing. The penetrometer consists of a steel ball having a diameter of 1%" mounted upon a rod having a smaller diameter which is attached to a pressure gauge. A measure of the toughness of the casing may be obtained by puncturing the stuffed casing with the steel ball. Inthe particular penetrometer employed in testing the sausage casings, the scale was calibrated in one-twentieths of a pound. Thefollowing data illustrate representativepenetrometer readings obtained by puncturing untreated casings and treated casings prepared as described above, employing the pineapple juice diluted with about 6 parts of water:

Untreated Treated casings casings Penetrometer Penelrometer reading wading The deviation in penetrometer readings of the untreated casings was 18 whereas the deviation in the case of the treated casings was 10. The data represent quite clearly that the treatment of the casings results in a far more uniform as well as tenderer product. By way of further inte rpretation of the above data on penetrometer tests, it

will be noted that the average reading for un-' treated casings is 83.16, whereas the average reading for treated casings is 57.5. Calculated in percentage, the resistance to penetration by the inch diameter steel ball was about 31 less for the treated casings than for the untreated casings. In other words, the sausages with treated casings offered about one-third less resistance to penetration by the ball than like sausages having untreated casings. a

In a more comprehensive test of other groups of casings similar results were obtained. In a statistical analysis of these data, it was found that the standard deviation between treated casings is about one-half as great as the standard deviation between untreated casings. The following table illustrates the results obtained in tests of with water.

. same size.

The process of the present invention also pro- 140 samples of treated casings and untreated casings:

If the resistance to penetration is calculated on the basis of the above average readings, it will be found that the treated casings offered about 38% less resistance topenetration than similar untreated casings. Again, the treated casings were roughly about one-third less resistant to penetration than untreated casings graded to the duces other improved properties in the treated casing. Among these are increased translucency and improved smoking properties. These improved properties appear to be due-at least in part to an increased quantity of water absorbed by the casing. The treatment of a casing with pineapple juice or a dilute aqueous solution of bromelin produces a noticeable tendency for the cas ing to swell accompanied by a marked increase in the amount of water absorbed by the casing. As a result, smoke penetrates the wet surface more rapidly and to a greater extent than the drier surface of an ordinary casing. Moreover, the casing dries out more slowly than an untreated casing and, as a result, provides a longer effective smoke period due to the more rapid and continued penetration of the smoke.

The increase in the water absorbing property of treated casings as compared to untreated casings may. be illustrated by the data given below. Casings graded to the same size were selected, one group being handled in the normal conventional manner, the other group being treated in accordance with the present invention. In the treatment of the casings in accordance with conventional practice, the salted casing were soaked in water to remove the salt and were then flushed The other group of casings was soaked in water for about 30 minutes to remove the salt, treated with a pineapple juice solution consisting of about 1 part of pineapple juice to 6 parts of water, held in contact with the applied enzyme at a temperature of from 70 to F. for about 2 hours, and then flushed with water. The percentage gain in weight of the treated and untreated casings was found to' be as follows:

Untreated cas- Treated case ings, per cent ings, per cent gain gain Average 35 87 ings in accordance with our invention increases the stretchability of the casings and thereby increases the stufllng capacity of the casings." In

scope thereof, and therefore only such limitations should be imposed as are indicated in the apsausage prepared from. a bundle of casings, each or the bundles containing 102 yards of easing.

Untreated Treated casings casings Mm. Mm. 28. 1 31. 2 28. 6 30. 7 28. 5 31. 1

Average 28.4 31.0

The sausages were also weighed'to obtain the weight of sausage meat. The data in the table which follows representthe weight of the stufled casing per standard bundle of 102 yards of casing.

Untreated Treated 08311188 casings Pounds Pounds 105. 110. 107. 5 120. 0 92. 0 112. 0

Average 101.8 lit 2 The increase in stumng capacity in the foregoing groups of casings was approximately 11%. The increase in stuiling capacity will, in general, vary from about 8% to-about'l5%, depending upon the characteristics of the casings. concentration of the juice used, and upon the length of the period of treatment 01 the casings. The above data illustrate a representative increase in the stretchability and stufling capacity of casings treated inaccordance with this invention.

. The treatment of the casings with the pro:

proteolytic plant enzymes renders the casings more slippery than conventional casings. Before stuffing, casings are placed upon or threaded on a stufling horn and it is desirable to have the casing as slippery as possible so that it may be easily threaded on the stufling horn, In conventional practice, a water connection is provided on the stuffing table and the operator places the casing over the water nozzle and admits a small.

amount of water prior to threading the casing upon the stufilng horn. Casings treated in accordance with our invention may be placed on the stuffing horn without first, admitting a small amount of water to the casing.

The dye absorption properties of the casings are also improved by the present process in that the casings require a smaller concentration of dye to produce the same intensity of color as compared to untreated casings. This is important when the product is labeled by stamping using a dye for the purpose. a

This application isa division of our continuation-in-part application, Serial No. 382,590, filed March 10, 1941, which in turn is a continuationin-part of our application, Serial No. 301,957, filed October 30, 1939, which application is a continuation-in-part or our application,-Serial No. 225,566, filed August 18, 1938.

Obviously, many modifications and variations of the invention hereinbefore set forth may be made without departing from the spirit anti to about 6% pended claims.

We claim: 7

1. Meat containing an aqueous solution of a proteolytic enzyme material in an amount equal of the weight of said meat to condition said meat for heat tenderizing treatment.

2. As a new article of commerce, an enzyme tenderized natural casing for use in making sausages and the like and characterized iurther by substantial increased stretchability as compared with an identical untenderized casing.

tenderness at least equal domestic sheep casings and said casing being 3. A new article of commerce for use in sausage 'manufacture, a normally tough natural casing enzyme tenderized to the extent that it has a further characterized by possessing only partial disintegration and yet having increased attributes of stretchability, translucency, smoking properties and slipperiness as compared with the natural untenderized product.

' teolytic plant Juice or other aqueous solution of 4. As a new article of making sausages, a tenderized hog casing having a tenderness at least equal to that of untenderized domestic sheep casings. 5. As a new article of commerce, hog casing for use terized by materially greater stretchability, translucency, smokability and slipperiness as compared to a similar untreated hog casing.

a tenderized 6. As a new article of commerce for use in making sausages, a tenderized natural casing characterized by increased stretchability enabling the same to receive at least 8' 3 more meat than could be stuffed into the same casing if untenderized.

'7. As a new article of commerce, an enzyme tenderized natural casing for use in making sausages and the like characterized by containing at least twice the amount of water as a like but untenderized casing graded to the same size.

8. Asa new product of manufacture, sausages having enzyme tenderized but only partially disintegrated natural casings and which tenderized casings are further characterized by greatly in! creased stretchability whereby to permit increased stuiling as compared with the identical untenderized product.

9; As a new product of manufacture, sausages in tenderized natural casings characterized by said casings having their resistance to penetration bya mf -inch diameter steel ball reduced by about one-third as compared with similar sausages in untenderized casings graded to the same size.

10. The product as defined in claim 7 which is further characterized by having its weight increased about 71 to 114% by absorption of water resulting from tenderization treatment.

11. The product as defined in claim 8 in which the casings are hog casings.

12. An enzyme tenderized normally tough natural casing characterized by only partial enzymic disintegration, possessing greatly increased stretchability to permit increased stuflability; enhanced tran'slucency, smokability and slipperiness and possessing substantially increased water,

' tissue characterized by substantially increased tenderness of the connective tissue component 'thcreoi and by a substantially increased moisture to that of untenderized Q commerce for use in in making sausages characcontent, as compared with an identical but untreated animal tissue, said animal tissue having been subjected to the action of an added proteolytic enzyme for a sufllcient time and at a temperature-within the active range of said pro- 14. The product as defined in claim 13 in which the enzymic action has been interrupted. before disintegration of the animal tissues by heat treatment. f

15. The product as defined in claim 13 which is characterized further by having had applied thereto an aqueous solution of proteolytic enzyme material in an amount equal toabout 6% of the weight of said product whereby to substantially 10 increase the moisture content of the product.

LEVI SCO'I'I PADDOCK. JOHN M. RAMSBQTTOM. 

